Estudio de la suplementación de la dieta materna con leucina durante la lactancia sobre la predisposición a la obesidad de la progenie e identificación de potenciales biomarcadores asociados

Laburpena

Introduction: Currently, there is a high prevalence of obesity in developed societies. Due to this fact, there is a growing interest for optimal nutrition and, for adequate and robust biomarkers of health/disease to help in the prediction of health outcome, to know whether an individual is predisposed to a disease, such as obesity, before it develops. So, this information can contribute to the implementation of nutritional strategies for prevention. - Research content: The study addressed in this Thesis aims to contribute to the identification and characterization of potential predictive biomarkers of obesity and/or associated metabolic disturbances. We have developed an animal model based on maternal leucine supplementation during lactation, based on the hypothesis that leucine supplementation might increase levels of leptin in breast milk. In this context, previous results of our research group demonstrated the protective role against obesity associated with the intake of optimal amounts of leptin in lactating male rats; and in relation to leucine, although there is some controversy whether beneficial or detrimental, it has been associated with obesity and insulin resistance. The results indicate that supplementation of standard diet with leucine (2%) in rats, promotes an increase in milk leptin, which is associated to the development of a male offspring protected, to some extent, against the development of obesity induced by high energy dense diets. However, it has the opposite effect on the female progeny, showing greater propensity for obesity and resistance to insulin action. Interestingly, the adverse effects on female offspring were counteracted by chronic leucine supplementation, while in the male offspring, this resulted in hyperinsulinemia. - Conclusion: A set of biomarkers have been identified, of which the following are selected for their potential interest in the field of obesity and for validation in other experimental models and humans: a) of increased susceptibility to obesity in females: lower expression of leptin, adiponectin and UCP2 in adipose tissue; b) better glycemic control in females: higher proportion of linoleic acid and lower of oleic and myristic acids in plasma; c) protection against obesity in males: leptin- and PUFA-enriched milk; d) of inadequate glycemic control in males: low plasma levels of linolenic acid and high plasma linoleic acid.